Something called Biodiversity net gain (BNG) starts becoming mandatory for a range of land developers from 12 February 2024 with Government publishing updates to guidance. Hereafter, developers will have to start showing how their developments can increase biodiversity by 10% either on site gains or by off-setting in order to receive a planning permission. In England, BNG becomes mandatory from 12 February 2024 under Schedule 7A of the Town and Country Planning Act 1990 (as inserted by Schedule 14 of the Environment Act 2021). 

The principle of BNG is straightforward – to leave a site with better biodiversity after a development than before. Some local authorities have had policies requiring biodiversity net gain – or at least no net loss – for a few years. BNG is a way of creating and improving natural habitats and makes sure development has a measurably positive impact (‘net gain’) on biodiversity, compared to what was there before development.  

You will need to understand the requirements of BNG if you are either a: 

• developer 
• local planning authority or
• land manager wanting to sell in the BNG market 

Michael Gove as environment secretary first promised to make protecting the natural world go “hand in hand” with building more homes, and so the government’s compulsory biodiversity net gain policy is finally being introduced: Mandatory BNG regulations in England will come into force from 12th February 2024 for major developments; from April 2024 for smaller sites; and from November 2025 for nationally significant infrastructure projects. 

In terms of smaller scale development on small sites, something called the Small Sites Metric (SSM) is an existing tool used to calculate the biodiversity value for small sites. Specifically, it allows for the assessment of biodiversity in the context of BNG for smaller areas. The key points about the Small Sites Metric are:

1. Purpose: The SSM is designed to evaluate the impact of development or projects on biodiversity in smaller sites.
2. Calculation: It quantifies the biodiversity value of a small site based on specific criteria, considering factors such as habitat quality, species richness, and ecosystem services.
3. User Guide: Natural England provides a comprehensive user guide that explains how to use the Small Sites Metric. This guide contains all the necessary information for accurate calculations and interpretation
4. Archived Version: The Small Sites Metric is part of the broader statutory biodiversity metric. While the statutory metric is hosted on the UK government website, the Small Sites Metric (version 4.0) has been archived separately

If your project qualifies as a small site, you can use the Small Sites Metric or the more detailed statutory biodiversity metric tool to assess biodiversity impact. Remember, these tools are valuable resources for promoting sustainable development and conservation efforts.